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Study of Pegcetacoplan (APL-2) in Patients with Transplant-associated Thrombotic Microangiopathy After Stem Cell Transplantation

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on patients with Transplant-associated Thrombotic Microangiopathy (TA-TMA), a condition that can occur after receiving a hematopoietic stem cell transplant. TA-TMA is a serious complication that affects small blood vessels and can cause damage to various organs. The study will test a medication called pegcetacoplan (also known as APL-2) in patients who have developed this condition after their transplant.

The purpose of this research is to understand how the body processes pegcetacoplan and to evaluate if it is safe and well-tolerated by patients with TA-TMA. The medication works by targeting part of the body's immune system known as the complement system, which plays a role in this condition.

This is an open-label study where all participants will receive pegcetacoplan. The study will monitor various aspects of patients' health, including blood tests and organ function, for 24 weeks. The research will look at how the medication affects certain proteins in the blood and whether it helps improve the symptoms of TA-TMA, including kidney function, blood cell counts, and other health measures.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial medical assessment

    A medical evaluation will confirm if you meet the study requirements after stem cell transplantation

    Your blood tests must show specific changes including low platelet count (below 50 x 109/L) and elevated LDH (a blood enzyme)

  2. Step 2

    Additional testing requirements

    You must have at least 2 additional markers from the following:

    Presence of specific blood cells called schistocytes in blood samples

    Low blood count (anemia) requiring blood transfusions

    Protein in urine (30 mg/dL or higher)

    Elevated levels of a protein called sC5b-9 in blood

    High blood pressure (140/90 mmHg or higher)

  3. Step 3

    Treatment period

    The study medication pegcetacoplan will be administered

    Treatment continues for 24 weeks

    Regular blood and urine tests will monitor your response to treatment

  4. Step 4

    Monitoring visits

    Your progress will be checked at week 12 and week 24

    Tests will measure changes in blood markers and organ function

    Your kidney, lung, digestive system, and nervous system function will be evaluated

    Blood pressure and other cardiovascular measurements will be taken

  5. Step 5

    Final assessment

    At week 24, final evaluations will determine if the treatment was successful

    Success is measured by improvement in blood test results and organ function

    Your need for blood transfusions will be assessed

    Long-term survival will be monitored up to 100 days from diagnosis

Who can join the trial?

8 criteria

  • Must be at least 18 years old at the time of signing consent
  • Must have received a stem cell transplant from a related or unrelated donor, using one of these sources: - Stem cells from blood - Bone marrow - Umbilical cord blood
  • Must have a diagnosis of transplant-associated TMA with the following signs: - Low platelet count (below 50 x 109/L or more than 50% decrease) - High LDH levels (a blood enzyme showing tissue damage) - At least 2 additional signs from: • Presence of damaged red blood cells in blood tests • Low blood hemoglobin or need for blood transfusions • Protein in urine • High levels of specific blood proteins (sC5b-9) • High blood pressure
  • Must have TMA that continues despite initial treatment
  • Must have elevated protein levels in urine (rUPCR ≥ 1 mg/mg)
  • For women who can become pregnant: - Must have negative pregnancy test - Must use approved birth control during study and 8 weeks after
  • For men: - Must avoid fathering children - Must use approved birth control - Must not donate sperm during study and 8 weeks after
  • Must be able to understand and sign the informed consent form

Who cannot join the trial?

14 criteria

  • Patients under 12 years old cannot participate
  • Patients who have had organ transplants other than stem cell transplants
  • Patients with active, uncontrolled bacterial, viral, or fungal infections
  • Patients who have received another experimental treatment within 30 days before starting this study
  • Pregnant or breastfeeding women
  • Patients with severe liver problems (defined as liver enzymes more than 3 times the normal level)
  • Patients with severe kidney problems (requiring regular dialysis - a process to filter blood when kidneys don't work properly)
  • Patients with active cancer that requires treatment
  • Patients with severe heart conditions
  • Patients who have had major surgery in the past 30 days
  • Patients who are allergic to any components of the study medication (pegcetacoplan)
  • Patients who cannot follow study procedures or attend scheduled visits
  • Patients with severe mental health conditions that could interfere with the study
  • Patients who are currently participating in another clinical trial
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Investigated drugs

Pegcetacoplan is a medication designed to treat patients who have developed blood vessel complications (thrombotic microangiopathy) after receiving a stem cell transplant. It works by targeting and regulating a part of the immune system called the complement system. This medication is administered to help manage and potentially improve the condition of patients who experience these transplant-related complications.

What is already known about the treatment

Pegcetacoplan – A novel therapeutic agent administered subcutaneously that works by targeting and inhibiting the complement protein C3, which plays a crucial role in the complement cascade system. This medication is being investigated for the treatment of Transplant-associated Thrombotic Microangiopathy (TA-TMA), a serious complication that can occur after hematopoietic stem cell transplantation. As a complement inhibitor, pegcetacoplan helps prevent excessive complement activation that leads to blood vessel damage and blood clot formation, making it a promising treatment option for patients who develop TA-TMA after transplantation.

Investigated diseases

Transplant-associated Thrombotic Microangiopathy (TA-TMA) - A rare complication that can occur after stem cell transplantation or organ transplantation. This condition affects small blood vessels throughout the body, causing damage to their walls and formation of blood clots. The disease process leads to the destruction of red blood cells, low platelet count, and can affect various organs including the kidneys. TA-TMA typically develops within the first 100 days after transplantation, though it can occur later. The condition causes changes in blood composition and can affect multiple organ systems.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-510443-37-00Protocol codeSobi.PEGCET-201Estimated enrolment15 patientsSponsorSwedish Orphan Biovitrum AB (publ)

sourced from the EU Clinical Trials Register and site verification

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